Answer:
-4
Step-by-step explanation:
ACtually to do this, you don't even need to do the graph or a calculator. In order to do this without the need of calculator or making a graph, you just need to either factorize the quadratic equation or solve for the value of X.
In this case, I'm going to factorize the equation.
x² - 5x - 36 = 0
Now, to do the factorization, we need to think in two numbers that:
1. When they are multiplied, the result is the third term of the equation (The independent term)
2. When they are sumed or substracted, the result is the second term of the equation (number with the x)
In this case, let's see which two numbers can give as result -36.
We have 6 * -6 = -36.
However these two numbers do not give -5 as a sum or substract of themselves. The other option is 9 and 4.
4 * -9 = -36
4 - 9 = -5
4 and -9 are the numbers. Therefore, the factorized equation would be:
(x + 4) (x - 9) = 0
So the values for x are -4 and 9.
With this, we can conclude that one solution for this equation is 4. You can do the graph if you wish.
